Air conditioning apparatus and method for controlling the same

ABSTRACT

An air conditioning apparatus may include an evaporator; a temperature sensor configured for detecting a temperature of the evaporator; a compressor compressing a refrigerant transmitted to the evaporator; a clutch selectively allowing power transmission from a vehicle power source to a compressor; and a controller connected to the clutch and configured for controlling the clutch to selectively allow the power transmission according to a result of comparison between a target temperature of the evaporator and a temperature detected by the temperature sensor, in which the controller sets the target temperature based on a vehicle driving state.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No.10-2019-0058987, filed on May 20, 2019, the entire contents of which isincorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an air conditioning apparatus and amethod for controlling the same, and more particularly, to an airconditioning apparatus, which may appropriately control power of acompressor provided in the air conditioning apparatus of a vehicle whenthe vehicle performs a departure driving or an overtake driving, and amethod for controlling the same.

Description of Related Art

In general, a vehicle may include an air conditioner supplying aninterior space of the vehicle with cold or warm air to control atemperature of the interior space, i.e., an air conditioning apparatus.

In general, the air conditioning apparatus may include a compressor, acondenser, an expansion valve and an evaporator provided as a heatexchanger. The compressor, the condenser, the expansion valve and theevaporator may be connected to each other through at least onerefrigerant passage. A refrigerant may flow in the compressor, thecondenser, the expansion valve and the evaporator through therefrigerant passage; and the cold or warm air may be generated from theair conditioning apparatus depending on a state change of the flowingrefrigerant. The generated cold or warm air may be provided to theinterior space of the vehicle through a fan.

Here, the compressor may be a component compressing the refrigerant andoperated by power provided from a vehicle power source such as anengine. A clutch may be provided to perform or block the powertransmission from the vehicle power source to the compressor. The clutchmay be controlled by a control signal provided by a controller of thevehicle (e.g., engine management system (EMS)) to perform or block thepower transmission to the compressor.

In a conventional air conditioning system, when the vehicle performs adeparture driving or an overtake driving, the clutch may block powertransmission, and thus reduce a load on the vehicle power source,providing a vehicle wheel with sufficient power. The presentconventional control system may be helpful in improving a drivingperformance of the vehicle. However, the power transmission to thecompressor is blocked and thus an interior cooling is impossible,causing a driver to feel uncomfortable in hot weather.

To solve the present problem, developed is a compressor configured forcontrolling a refrigerant discharge capacity using an electronic controlvalve depending on a predetermined temperature and a vehicle drivingenvironment. The compressor with the present electronic control valvemay control the refrigerant discharge capacity depending on the vehicledriving environment and thereby may change an operation rate of thecompressor. Accordingly, when the vehicle performs the departure drivingor the overtake driving, the compressor may provide the interior spaceof the vehicle with the cool air, while providing the vehicle wheel withthe sufficient power.

However, such a configuration in which the air conditioning apparatusutilizes the compressor including the electronic control valve may notbe a solution. The reason is that the above air conditioning apparatusmay not simultaneously provide the driving performance and an interiorair conditioning to a vehicle already in driving without the electroniccontrol valve. Furthermore, the compressor including the electroniccontrol valve is relatively expensive, and thus may raise a price of thevehicle even when used in a new vehicle later.

The information included in this Background of the present inventionsection is only for enhancement of understanding of the generalbackground of the present invention and may not be taken as anacknowledgement or any form of suggestion that this information formsthe prior art already known to a person skilled in the art.

BRIEF SUMMARY

Various aspects of the present invention are directed to providing anair conditioning apparatus which may properly control power of acompressor based on a vehicle driving state, rather than blocking thepower of the compressor provided in the air conditioning apparatus whenthe vehicle performs a departure driving or an overtake driving, and amethod for controlling the same.

According to an exemplary embodiment in an exemplary embodiment of thepresent invention, an air conditioning apparatus may include: anevaporator; a temperature sensor configured for detecting a temperatureof the evaporator; a compressor compressing a refrigerant transmitted tothe evaporator; a clutch selectively allowing power transmission from avehicle power source to a compressor; and a controller connected to theclutch and configured for controlling the clutch to selectively allowthe power transmission according to a comparison between a targettemperature of the evaporator and a temperature detected by thetemperature sensor, in which the controller sets the target temperaturebased on a vehicle driving state.

The controller may set the target temperature based on an acceleratorpedal depressed amount of the vehicle and a revolutions per minute ofthe vehicle power source in the vehicle driving state.

The controller may include a data map including the target temperatureof the evaporator which is stored in advance depending on theaccelerator pedal depressed amount of the vehicle and the revolutionsper minute of the vehicle power source, and may set the targettemperature by applying detected values of the accelerator pedaldepressed amount of the vehicle and the revolutions per minute of thevehicle power source to the data map.

The data map may include a data map for a departure driving in which thevehicle performs the departure driving and a data map for an overtakedriving in which the vehicle is on the overtake driving.

The controller may set the target temperature using the data map for adeparture driving when a vehicle speed is less than a predeterminedreference speed, and using the data map for an overtake driving when thevehicle speed is equal to or greater than the predetermined referencespeed.

The controller may correct the target temperature by multiplying thetarget temperature set using the data map by a correction valuedepending on an external air temperature, and determine whether or notthe clutch is to perform or block the power transmission based on thecorrected target temperature.

The correction value may be relatively smaller as the external airtemperature is higher.

According to another exemplary embodiment in an exemplary embodiment ofthe present invention, a method for controlling an air conditioningapparatus may include: receiving detected values of an accelerator pedaldepressed amount of a vehicle, a vehicle speed, and a revolutions perminute of a vehicle power source (engine); determining a vehicle drivingstate based on the detected vehicle speed value, selecting a data mapstoring a target temperature of an evaporator in advance depending onthe accelerator pedal depressed amount of the vehicle and therevolutions per minute of the vehicle power source based on thedetermined vehicle driving state, and setting the target temperature ofthe evaporator by applying the detected values of the accelerator pedaldepressed amount of the vehicle and the revolutions per minute of thevehicle power source to the selected data map; and determining whetheror not a clutch is to perform or block power transmission according to acomparison result between the target temperature of the evaporator and atemperature detected by a temperature sensor.

The data map may include a data map for a departure driving in which thevehicle performs the departure driving and a data map for an overtakedriving in which the vehicle is on the overtake driving.

In the setting of the target temperature of the evaporator, the targettemperature may be set using the data map for a departure driving when avehicle speed is less than a predetermined reference speed, and usingthe data map for an overtake driving when the vehicle speed is equal toor greater than the predetermined reference speed.

The method may further include, after the setting of the targettemperature of the evaporator, receiving an external air temperature ofthe vehicle; and correcting the target temperature by multiplying thetarget temperature set using the data map by a correction valuedepending on an external air temperature.

In the determining of whether or not the clutch is to perform or blockthe power transmission, it may be determined whether or not the clutchis to perform or block the power transmission according to a comparisonresult between the target temperature corrected in the correcting of thetarget temperature and a temperature detected by the temperature sensor.

The correction value may be relatively smaller as the external airtemperature is higher.

The methods and apparatuses of the present invention have other featuresand advantages which will be apparent from or are set forth in moredetail in the accompanying drawings, which are incorporated herein, andthe following Detailed Description, which together serve to explaincertain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an air conditioning apparatusaccording to an exemplary embodiment in an exemplary embodiment of thepresent invention.

FIG. 2 and FIG. 3 are views each illustrating an example of a targettemperature of an evaporator set by a controller in an air conditioningapparatus according to an exemplary embodiment in an exemplaryembodiment of the present invention.

FIG. 4 is a view exemplarily illustrating a relationship between a powerof a compressor and a target temperature of an evaporator in an airconditioning apparatus according to an exemplary embodiment in anexemplary embodiment of the present invention.

FIG. 5 is a Mollier diagram illustrating an example of setting therelationship between the target temperature and the power of thecompressor as illustrated in FIG. 4.

FIG. 6 is a view exemplarily illustrating an example of a correctionvalue used when setting a target temperature in an air conditioningapparatus according to an exemplary embodiment in an exemplaryembodiment of the present invention.

FIG. 7 is a flowchart illustrating a method for controlling an airconditioning apparatus according to an exemplary embodiment in anexemplary embodiment of the present invention.

It may be understood that the appended drawings are not necessarily toscale, presenting a somewhat simplified representation of variousfeatures illustrative of the basic principles of the present invention.The specific design features of the present invention as includedherein, including, for example, specific dimensions, orientations,locations, and shapes will be determined in part by the particularlyintended application and use environment.

In the figures, reference numbers refer to the same or equivalentportions of the present invention throughout the several figures of thedrawing.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments of thepresent invention(s), examples of which are illustrated in theaccompanying drawings and described below. While the presentinvention(s) will be described in conjunction with exemplary embodimentsof the present invention, it will be understood that the presentdescription is not intended to limit the present invention(s) to thoseexemplary embodiments. On the other hand, the present invention(s)is/are intended to cover not only the exemplary embodiments of thepresent invention, but also various alternatives, modifications,equivalents and other embodiments, which may be included within thespirit and scope of the present invention as defined by the appendedclaims.

Hereinafter, an air conditioning apparatus and a method for controllingthe same according to embodiments in an exemplary embodiment of thepresent invention are described with reference to the accompanyingdrawings.

FIG. 1 is a block diagram illustrating an air conditioning apparatusaccording to an exemplary embodiment in an exemplary embodiment of thepresent invention.

Referring to FIG. 1, an air conditioning apparatus according to anexemplary embodiment in an exemplary embodiment of the present inventionmay include: an evaporator 20; a temperature sensor 30 detecting atemperature of the evaporator 20; a compressor 10 compressing arefrigerant transmitted to the evaporator; a clutch 11 performing orblocking the power transmission from a vehicle power source to acompressor 10; and a controller 100 controlling the clutch 11 accordingto a comparison result between a target temperature of the evaporator 20and a temperature detected by the temperature sensor 30.

In general, an air conditioning apparatus provided in a vehicle mayinclude the compressor 10, the clutch 11, a condenser, the evaporator20, a passage connecting the compressor 10 and the condenser, a passageconnecting the condenser and the evaporator 20, and a passage connectingthe evaporator 20 and the compressor 10. The compressor 10, thecondenser, the evaporator 20 and a plurality of passages may beconnected to each other to allow the refrigerant to flow in apredetermined direction thereof

The compressor 10 may be supplied with a refrigerant in a low-pressuregaseous state through the passage connected to the evaporator 20, andmay convert the supplied refrigerant into a refrigerant in ahigh-temperature and high-pressure gaseous state. The refrigerant in ahigh-temperature and high-pressure gaseous state may be transmitted tothe condenser through the passage connected to the condenser.

The clutch 11 may be connected to the compressor 10 and controlled bythe controller 100 to transmit power of the vehicle power source (e.g.,engine) to the compressor 10 to operate the compressor 10.Alternatively, the clutch 11 may block the power transmission from thevehicle power source to the compressor 10 to stop an operation of thecompressor 10.

Although not illustrated, the condenser may cool and thus liquefy therefrigerant in a high-temperature and high-pressure gaseous state, whichis transmitted from the compressor 10, into a refrigerant in a liquidstate. In an external heat exchanger, the refrigerant may release heatto the outside, while being liquefied, and thus a temperature of therefrigerant may be lowered. The refrigerant cooled in the condenser maybe transmitted to the evaporator 20 through the passage connected to theevaporator 20.

The evaporator 20 may be provided to discharge the cold air using therefrigerant provided from the condenser. The evaporator 20 may include apassage through which the refrigerant flows, and the passage may beimplemented using a tube formed of a metal or a synthetic resinmaterial. The tube may be bent in multiple turns to have a zig-zagshape.

In detail, while the refrigerant passes through the evaporator 20, therefrigerant may absorb latent heat and evaporate, lowering a temperatureof air around the evaporator 20. Accordingly, the cold air may begenerated around the evaporator 20, and the generated cold air may besupplied to an interior space of the vehicle through a fan.

The refrigerant discharged from the evaporator 20 may be transmittedback to the compressor 10 through the passage connected to thecompressor 10.

The controller 100 may perform an electronic control of variouscomponents provided in the vehicle. The controller 100 may include acentral processing unit (CPU), a microcontroller unit (MCU), anelectronic control unit (ECU) or the like. The CPU, the MCU, the ECU orthe like may be implemented using one or more semiconductor chips andassociated components. Furthermore, the CPU, the MCU, the ECU or thelike may perform processing for various operations of the vehicle basedon a program or data which is embedded or input by a user. The CPU, theMCU, the ECU or the like may be installed at any position inside thevehicle depending on a designer's choice. For example, the CPU, the MCU,the ECU or the like may be installed on a board, and the board may bemounted in a space between a dashboard and an engine compartment.

In an exemplary embodiment in an exemplary embodiment of the presentinvention, the controller 100 may include an engine management systemcontrolling an operation of the clutch 11 which is implemented as aseparate control unit in a real vehicle, and an air conditioningapparatus controller configured for controlling the air conditioningapparatus. The controller 100 may be operated by coordinated control ofthe engine management system and the air conditioning apparatuscontroller.

In an exemplary embodiment in an exemplary embodiment of the presentinvention, the controller 100 may compare the target temperature of theevaporator 20 with an actual temperature of the evaporator 20 detectedby the temperature sensor 30 (hereinafter, a detection temperature) todetermine whether or not the clutch 11 is to perform or block the powertransmission.

In general, the air conditioning apparatus of the vehicle may controlthe evaporator 20 to have the target temperature immediately beforefreezing (e.g., 1 to 3 deg. C.) to prevent freezing of the evaporator 20and to exhibit maximum cooling performance of the vehicle. Thecontroller 100 may control the clutch 11 to block the power transmissionto the compressor 10 when the detection temperature is lower than thetarget temperature, and may control the clutch 11 to transmit the powerto the compressor 10 when the detection temperature is higher than thetarget temperature. Naturally, a constant hysteresis may be used whenthe clutch 11 is controlled as such. For example, the controller 100 maycontrol the clutch 11 to transmit the power to the compressor 10 whenthe detection temperature is higher than a value obtained by the targettemperature-plus-a preset margin temperature.

Furthermore, the controller 100 may determine whether or not the vehicleperforms the departure driving or the overtake driving based on avehicle driving state and set the target temperature based on a resultof the determination. The controller 100 may determine whether or notthe vehicle performs the departure driving or the overtake driving basedon an accelerator pedal depressed amount of the vehicle detected by avehicle accelerator pedal position sensor, a vehicle speed detected by avehicle speedometer and a revolutions per minute (RPM) of the vehiclepower source detected by an RPM sensor which detects the RPM of thevehicle power source, e.g., the engine.

When it is determined that the vehicle performs the departure driving orthe overtake driving, the controller 100 may set the target temperaturedifferent for each of a plurality of sections divided based on the APSand the RPM of the vehicle power source.

FIG. 2 and FIG. 3 are views each illustrating an example of a targettemperature of an evaporator set by a controller in an air conditioningapparatus according to an exemplary embodiment in an exemplaryembodiment of the present invention. Furthermore, FIG. 4 is a viewexemplarily illustrating a relationship between power of a compressorand a target temperature of an evaporator in an air conditioningapparatus according to an exemplary embodiment in an exemplaryembodiment of the present invention.

The controller 100 may include data maps for controlling the compressoras illustrated in FIG. 2 and FIG. 3. The controller 100 may use the datamap as illustrated in FIG. 2 when the vehicle speed is less than apredetermined reference speed, and may use the data map as illustratedin FIG. 3 when the vehicle speed is equal to or greater than thepredetermined reference speed.

As illustrated in FIG. 2 and FIG. 3, each data map may have a pluralityof sections divided based on the APS and the RPM of the vehicle powersource, and may use a target temperature different for each sectiondepending on demand power of the vehicle wheel required for thedeparture driving or the overtake driving of the vehicle.

A table of FIG. 4 illustrates cases in which a total of four differenttarget temperatures are respectively used in four stages. Stage 1 is acase in which the demand power of the vehicle wheel required for thedeparture driving or the overtake driving of the vehicle is greatest,and stage 4 is a case in which the cooling performance of the vehiclemay be maximized when it is determined that the vehicle performs neitherthe departure driving nor the overtake driving.

For example, stage 1 in the table of FIG. 4 is a stage in which thedemand power of the vehicle wheel required for the departure driving orthe overtake driving of the vehicle is greatest, and thus the targettemperature of the evaporator is set to the highest level to minimizethe cooling performance of the air conditioning apparatus. Next, stage 2in the table of FIG. 4 is a middle stage of the departure driving or theovertake driving of the vehicle, in which the demand power of thevehicle wheel required for the departure driving or the overtake drivingof the vehicle is smaller than that in stage 1 and thus the targettemperature in stage 2 may be set to be lower than the targettemperature in stage 1.

Furthermore, stage 3 in the table of FIG. 4 is an early stage of thedeparture driving or the overtake driving of the vehicle, in which thedemand power of the vehicle wheel required for the departure driving orthe overtake driving of the vehicle is smaller than that in stage 2 andthus the target temperature in stage 3 may be set to be lower than thetarget temperature in stage 2. Finally, stage 4 in the table of FIG. 4is a stage, in which the cooling performance of the vehicle may bemaximized on condition that the vehicle performs neither the departuredriving nor the overtake driving and thus the target temperature instage 4 may be set to be lower than the target temperature in stage 3(i.e., the target temperature for preventing freezing of theevaporator).

The target temperature of the evaporator 20 set in the table of FIG. 4may be determined using an experimental technique in advance consideringthe temperature of the evaporator 20 and dynamic performance of thecompressor 10. In the instant case, a Mollier diagram as illustrated inFIG. 5 may be used. FIG. 5 is a Mollier diagram illustrating an exampleof setting the relationship between the target temperature and the powerof the compressor as illustrated in FIG. 4.

For example, in stage 1 in which the demand power of the vehicle wheelrequired for the departure driving or the overtake driving of thevehicle is greatest, the target temperature of the evaporator 20 may beset to 15.0° C. to make the compressor operate with about 40.1% ofmaximum power thereof. That is, considering the experimental techniqueor the dynamic performance of the compressor 10 in advance, thetemperature of the evaporator 20 may be found for making the power ofthe compressor 10 to be 40.1% of the maximum power thereof and the foundtemperature of the evaporator 20 may be set to the target temperature ofstage 1. The stages may be set by plotting a line corresponding to acompression process on the Mollier diagram as illustrated in FIG. 5 tocorrespond to the dynamic performance of the compressor.

FIG. 2, FIG. 3, FIG. 4 and FIG. 5 illustrate an example of performingcontrol by dividing the target temperature into four stages depending onthe demand power of the vehicle wheel. This is only an example providedfor the understanding of the present invention, and the presentinvention is not limited thereto. Also, it is very obvious to thoseskilled in the art that the target temperature may be divided intomultiple stages rather than in four stages.

FIG. 6 is a view exemplarily illustrating an example of a correctionvalue used when setting a target temperature in an air conditioningapparatus according to an exemplary embodiment in an exemplaryembodiment of the present invention.

As illustrated in FIG. 6, the correction value used when setting thetarget temperature may be set to a smaller value as an external airtemperature is higher. As explained in FIG. 2, FIG. 3 and FIG. 4, thecorrection value set as in FIG. 6 is a value for correcting the targettemperature set based on a vehicle driving state, and the controller 100may multiply the target temperature set using the data map of FIG. 2 andFIG. 3 by the correction value to finally derive the target temperatureof the evaporator 20 for controlling the compressor 10.

The higher the external air temperature, the higher the driver's demandfor the air conditioning performance of the vehicle. Therefore, when theexternal air temperature is high, it is desirable to meet driver'sdemand for the air conditioning performance by setting the targettemperature relatively lower than when the external air temperature islow. To the contrary, when the external air temperature is low, thetarget temperature may be set relatively higher than when the externalair temperature is high, relatively reducing the air conditioningperformance and improving the dynamic performance of the vehicle in thedeparture driving or in the overtake driving.

FIG. 7 is a flowchart illustrating a method for controlling an airconditioning apparatus according to an exemplary embodiment in anexemplary embodiment of the present invention.

The method for controlling the air conditioning apparatus as illustratedin FIG. 7 is a controlling method performed in a controller of an airconditioning apparatus according to various embodiments in an exemplaryembodiment of the present invention as described above. First, acontroller 100 may receive an accelerator pedal depressed amount of avehicle, a vehicle speed and a revolutions per minute (RPM) of a vehiclepower source (e.g., engine) (S11).

Next, the controller 100 may select a target temperature data map storedin advance to control a compressor 10 based on the input vehicle speed(S12).

For example, in step S12, the controller 100 may select a data map for adeparture driving as illustrated in FIG. 2 when the vehicle speed isless than a predetermined reference speed, and may select a data map foran overtake driving as illustrated in FIG. 3 when the vehicle speed isequal to or greater than the predetermined reference speed.

Furthermore, in step S12, the controller 100 may set a targettemperature of an evaporator 20 for controlling the compressor 10 byapplying the APS input and the RPM of the vehicle power source to theselected data map.

Next, the controller 100 may then receive information on an external airtemperature of the vehicle from an external air temperature sensor ofthe vehicle and as illustrated in FIG. 6, may set a correction value inadvance for the external air temperature (S13).

Next, the controller 100 may multiply the target temperature set basedon a vehicle driving state(the APS and the RPM of the vehicle powersource) in step S12 by the correction value set in step S13 to finallydetermine the target temperature of the evaporator 20 (S14).

Next, the controller 100 may compare the target temperature finallydetermined in step S14 with a detection temperature of the evaporator 20detected by a temperature sensor 30 and thus control the clutch toperform or block power transmission, controlling power of the compressor10.

As described above, according to the air conditioning apparatus and themethod for controlling the same according to various embodiments in anexemplary embodiment of the present invention, when the vehicle isrequired to perform the departure driving or the overtake driving, thepower of the compressor may be indirectly controlled by changing thetarget temperature of the evaporator used to control the temperature ofthe evaporator, rather than simply using the clutch to block the powertransmission to the compressor. Therefore, by controlling the power ofthe compressor depending on the demand power of the vehicle wheelrequired for the departure driving or the overtake driving of thevehicle, the air conditioning apparatus in an exemplary embodiment ofthe present invention may secure both the driving performance of thevehicle and a certain level of the interior cooling performance of thevehicle.

Furthermore, the air conditioning apparatus and the method forcontrolling the same according to various embodiments in an exemplaryembodiment of the present invention may change the target temperature ofthe evaporator used for controlling the compressor depending on theexternal air temperature, and thus may reflect the driver's demand forthe interior cooling depending on the external air temperature,providing a more comfortable driving environment to the driver.

Effects obtainable in an exemplary embodiment of the present inventionare not limited to the effects mentioned above. That is, other effectsthat are not mentioned may be obviously understood by those skilled inthe art to which an exemplary embodiment of the present inventionpertains from the following description.

For convenience in explanation and accurate definition in the appendedclaims, the terms “upper”, “lower”, “inner”, “outer”, “up”, “down”,“upwards”, “downwards”, “front”, “rear”, “back”, “inside”, “outside”,“inwardly”, “outwardly”, “internal”, “external”, “inner”, “outer”,“forwards”, and “backwards” are used to describe features of theexemplary embodiments with reference to the positions of such featuresas displayed in the figures. It will be further understood that the term“connect” or its derivatives refer both to direct and indirectconnection.

The foregoing descriptions of specific exemplary embodiments of thepresent invention have been presented for purposes of illustration anddescription. They are not intended to be exhaustive or to limit thepresent invention to the precise forms disclosed, and obviously manymodifications and variations are possible in light of the aboveteachings. The exemplary embodiments were chosen and described toexplain certain principles of the present invention and their practicalapplication, to enable others skilled in the art to make and utilizevarious exemplary embodiments of the present invention, as well asvarious alternatives and modifications thereof. It is intended that thescope of the present invention be defined by the Claims appended heretoand their equivalents.

What is claimed is:
 1. An air conditioning apparatus comprising: anevaporator; a temperature sensor configured for detecting a temperatureof the evaporator; a compressor compressing a refrigerant transmitted tothe evaporator; a clutch selectively allowing power transmission from apower source of a vehicle to the compressor; and a controller connectedto the clutch and configured for controlling the clutch to selectivelyallow the power transmission according to a result of comparison betweena target temperature of the evaporator and the temperature detected bythe temperature sensor, wherein the controller is configured to set thetarget temperature based on a driving state of the vehicle.
 2. The airconditioning apparatus of claim 1, wherein the power source includes anengine of the vehicle, and wherein the controller is configured to setthe target temperature based on an accelerator pedal depressed amount ofthe vehicle and a revolutions per minute (RPM) of the engine in thedriving state of the vehicle.
 3. The air conditioning apparatus of claim1, wherein the power source includes an engine of the vehicle, whereinthe controller includes a data map including the target temperature ofthe evaporator which is stored in advance depending on an acceleratorpedal depressed amount of the vehicle and a revolutions per minute (RPM)of the engine, and wherein the controller is configured to set thetarget temperature by applying the accelerator pedal depressed amount ofthe vehicle and the RPM of the engine to the data map.
 4. The airconditioning apparatus of claim 3, wherein the data map includes: afirst data map for a departure driving in which the vehicle is on thedeparture driving; and a second data map for an overtake driving inwhich the vehicle is on the overtake driving.
 5. The air conditioningapparatus of claim 4, wherein the controller is configured to set thetarget temperature, by using the first data map for the departuredriving, upon determining that a vehicle speed is less than apredetermined reference speed, and by using the second data map for theovertake driving, upon determining that the vehicle speed is equal to orgreater than the predetermined reference speed.
 6. The air conditioningapparatus of claim 3, wherein the controller is configured to correctthe target temperature by multiplying the target temperature set usingthe data map by a correction value depending on an external airtemperature, and wherein the controller is configured to determine whenthe clutch is to selectively allow the power transmission based on thecorrected target temperature.
 7. The air conditioning apparatus of claim6, wherein the correction value is set to be smaller as the external airtemperature is higher.
 8. A method of controlling an air conditioningapparatus including an evaporator, a temperature sensor configured fordetecting a temperature of the evaporator, a compressor compressing arefrigerant transmitted to the evaporator, a clutch selectively allowingpower transmission from a power source of a vehicle to the compressor,and a controller connected to the clutch, the method comprising:receiving, by the controller, detected values of an accelerator pedaldepressed amount of the vehicle, a vehicle speed, and a revolutions perminute (RPM) of an engine in the vehicle; determining, by thecontroller, a driving state of the vehicle based on the detected valueof the vehicle speed, selecting a data map including a targettemperature of the evaporator, which is stored in advance depending onthe accelerator pedal depressed amount of the vehicle and the RPM of theengine based on the determined driving state of the vehicle, and settingthe target temperature of the evaporator by applying the detected valuesof the accelerator pedal depressed amount of the vehicle and the RPM ofthe engine to the selected data map; and determining, by the controller,of when the clutch is to selectively allow the power transmissionaccording to a result of comparison between the target temperature ofthe evaporator and the temperature detected by the temperature sensor;and controlling, by the controller, the clutch to selectively allow thepower transmission according to the result of comparison between thetarget temperature of the evaporator and the temperature detected by thetemperature sensor.
 9. The method of claim 8, wherein the data mapincludes: a first data map for a departure driving in which the vehicleis on the departure driving and a second data map for an overtakedriving in which the vehicle is on the overtake driving.
 10. The methodof claim 9, wherein in the setting of the target temperature of theevaporator, the target temperature is set by using the first data mapfor the departure driving, upon determining that the vehicle speed isless than a predetermined reference speed, and by using the second datamap for the overtake driving, upon determining that the vehicle speed isequal to or greater than the predetermined reference speed.
 11. Themethod of claim 8, further including: after the setting of the targettemperature of the evaporator, receiving an external air temperature ofthe vehicle; and correcting the target temperature by multiplying thetarget temperature set using the data map by a correction valuedepending on the external air temperature.
 12. The method of claim 11,wherein in the determining of when the clutch is to selectively allowthe power transmission, the clutch is determined to selectively allowthe power transmission according to the result of comparison between thetarget temperature corrected in the correcting of the target temperatureand the temperature detected by the temperature sensor.
 13. The methodof claim 11, wherein the correction value is set to be smaller as theexternal air temperature is higher.